Underfloor heating air-water heat pump. House too warm when the sun shines

So ours is completely escalating right now. At minus 8 degrees, we need 38 kWh of electricity daily. The system has now automatically lowered the hot water temperature from 48 to 44 degrees. It can't manage any more at the outside temperature.

Sometimes I long for the gas heating back, especially in winter :(

There is still something wrong with yours. The heat pump is actually oversized if I remember correctly.

Something is still wrong with you. If I remember correctly, the heat pump is even oversized.

Yes, according to the heating load calculation not, but that is always on the safe side. It is definitely one size too big. Strange though, why it no longer manages the hot water then. Does nobody else here have that problem?

So far we don’t have that problem. It’s currently -7° outside temperature. I need to check the consumption, at the moment we have everything connected to one meter, so I have to take a look at how to calculate that. I’m really happy with the photovoltaic system! When it’s sunny, we basically heat for free.

but not in winter ;)

Yes, according to the heating load calculation, no, but that is always on the safe side. It is definitely one size too big. Strange though, why it then can no longer handle the hot water. Does no one else here have that problem?

Is the time sufficient to prepare HW? Including defrosting process possibly?

Yes, according to the heat load calculation, no, but it is always on the safe side. It is definitely one size too big. Strange though, why it then can’t handle the hot water anymore. Does no one else here have this problem?

Maybe the max. heating capacity for hot water is limited?
I don’t know your model. In ours (modulating), the max. heating capacity for heating operation is limited to 80% and for hot water to 70% according to factory settings. But I only found out a few days ago when I browsed a bit on the technician level.
At the outside temperatures, the capacity might no longer be enough. So at -8 degrees, the pump would probably have to run at full speed to nearly reach the required kW output...

No idea, just an idea...